The present disclosure relates generally to semiconductor devices; and more particularly, to the protection of semiconductor devices from high voltage junction stresses. Still more particularly, the present disclosure relates to a modified switch design and method to reduce its high voltage junction stresses, thereby decreasing the required integrated circuit (IC) high voltage requirement.
Complementary metal oxide semiconductor (CMOS) technology is a preferred fabrication process for many integrated circuit devices, particularly those wherein low power consumption and high component density are important considerations. These devices may be found in laptops and other portable electronic devices. For example, these portable electronic devices utilize memory devices such as erasable programmable read only memories (EPROMs), and electrically erasable programmable read only memories (EEPROMs). Typically, a low voltage signal is used to switch on a high voltage output, which is then used to operate the memories. In other words, a low voltage input signal (typically 0.5 to 2 volts) is used to switch high voltage outputs (typically 13 to 15 volts) for circuits such as row and column address decoders, signal level translators, programming circuits, and output pad drivers.
The structure of CMOS technologies is dependent upon the required performance of the CMOS device. Since the structure of semiconductors designed to operate at high voltages; e.g., to withstand a high voltage junction stress, is different from the structure of semiconductors designed to operate at regular voltages, additional IC fabrication steps and fabrication masks are required to produce circuitries whose operating voltages include regular and high voltages. The requirement of extra fabrication steps and fabrication masks result in a longer processing cycle and higher processing costs.
Desirable in the art of semiconductor devices are additional designs that reduce high voltage junction stresses, thereby decreasing the required IC high voltage requirement and hence the required fabrication steps.